Dishwasher

A dishwasher comprising:

• a tub that defines a washing compartment;
• a door disposed at a front side of the tub and configured to open and close the washing compartment;
• a first rack disposed in the washing compartment and configured to support one or more objects to be washed;
• a first spray arm disposed below the first rack and configured to spray wash water toward the first rack;
• a second rack disposed in the washing compartment and configured to support one or more objects to be washed;
• a second spray arm rotatably disposed in the washing compartment and configured to spray wash water toward the second rack, the second spray arm being configured to be disposed at a plurality of adjustable placement heights;
• a magnet disposed at the second spray arm;
• and
• a sensor disposed at the door and configured to detect magnetic force of the magnet,
• wherein a height of the sensor is greater than a width of the sensor.

A dishwasher comprising:

• a tub that defines a washing compartment;
• a sump connected to the tub and configured to store wash water;
• a water supply pipe that connects an external water source to the sump;
• a water supply valve configured to regulate supply of water through the water supply pipe;
• a pump connected to the sump and configured to supply the wash water from the sump to the tub;
• a first spray arm disposed in the washing compartment, the first spray arm being configured to spray the wash water supplied from the pump to the tub;
• a second spray arm disposed above the first spray arm in the washing compartment, the second spray arm being configured to rotate;
• a switching valve configured to selectively connect any one of the first spray arm or the second spray arm to the pump;
• a sensor configured to detect rotation of the second spray arm;
• a controller configured to control the water supply valve, the pump, and the switching valve;
• and
• a memory configured to store information including a preset wash course,
• wherein the controller is configured to:
• open the water supply valve to supply water from the external water source to the sump,
• control the switching valve to connect the second spray arm to the pump,
• operate the pump after supplying the water to the sump and connecting the second spray arm to the pump, and
• based on the sensor detecting that the rotation the second spray arm is restrained while the pump operates, output information indicating a rotation-restrained state of the second spray arm.